After a summer in which they signed just one big name and a first half of the season that saw them fall well down the Premier League table and out of the FA Cup, January has become a very important month for Manchester United.

Manchester United have stepped up their efforts to bolster their ailing squad after they watched Diego Costa and Ander Herrera this weekend.

After tumbling out of the FA Cup to Swansea, a defeat which lurched United’s season to a new low, manager David Moyes admitted there is an 'urgency' at Old Trafford to recruit players.

He has been searching Europe for a new left back, midfielder and a striker.

Adds King:

Herrera was wanted by United in the summer but their attempts to land the former Spain Under 21 midfielder fell asunder on deadline day, when they failed to meet a £30m release clause in his contract. He has two-and-a-half years remaining on that deal.

Bilbao are in contention for a Champions League place but Moyes may yet go back with a renewed attempt to land the 24-year-old, given how stretched United have become in midfield due to mounting injuries.

While the Costa interest is a bit of a head-scratcher—yes, the team is beat up at forward at the moment, but they still have a lot of depth in attacking positions—a revitalized interest in Ander Herrera absolutely, positively makes sense for United.

Even if he is overpriced.

Without question, United's biggest weakness is a pretty disappointing central midfield. While Michael Carrick has once again been solid, Marouane Fellaini has battled injuries, Tom Cleverly has underwhelmed and Darren Fletcher has just returned and probably is better served deputizing behind a starting pair.

Herrera would be a nice partner for Carrick. Whereas the latter likes to play deeper, Herrera is a technically sound player that is capable of unlocking opposing defenses with incisive passing and excellent vision.

Unlike Carrick, he's more comfortable playing up the pitch, and while he won't score many goals, he'll certainly help to facilitate his fair share. But he's not a pure attacking mid, as he isn't afraid to get back on defense and win a tackle or earn a crucial interception of a pass.

He's not a pure box-to-box player, but he's certainly just what the doctor ordered for this United team. So will they pony up and match his pretty substantial release clause this time around? If they won't, will Athletic Bilbao be willing to negotiate a slightly lower transfer fee?

If United are to claw their way back into the Premier League, shoring up the midfield would be a nice first step. Herrera may not be the mega-superstar the United faithful crave, but he would definitely help this team from Day 1.

At the end of the day at Old Trafford, that's all that really matters.